I've had my Lumia 920 just over 5 weeks now and using the Lumia storage check app, my Other is at 1.4 GB. I've been monitoring it ever since I got the phone, and the only time I've really seen it grow is whenever I manually save photos to Skydrive, or use the facebook app. I'm guessing the app cache files from facebook and other apps like baconit contribute to Other storage. Sad since there should be a way to delete those temp cache files from the app itself. On my old Android phone, I saw the facebook app use a ton of temp file space if I didn't constantly monitor it and go and delete those files every day. So lately I have not saved any photos to Skydrive and have been using the People Hub more for checking facebook notifications rather than the fb app and I have not seen Other grow more than 1.4 GB in a few weeks now. I don't install or play games either if that helps.
Still would like to see a permanent fix soon from Nokia & MS :asleep: